Spectroscopic assembly and method

1. A sensor comprising:

a photodetector configured to convert received light into a current indicative of an intensity of the received light; and

an optical filter configured to:

prevent light having a wavelength outside a bandpass region from reaching the photodetector, and

pass light having a wavelength within the bandpass region to the photodetector,

wherein a percentage of light passing through the optical filter decreases as an angle of incidence of light increases from 0 degrees to 89 degrees, and

wherein an amplitude of transmission decreases as the angle of incidence of light increases.

2. The sensor of claim 1 , wherein the optical filter is a low angle sensitive optical filter.

3. The sensor of claim 1 , wherein the optical filter has low sensitivity to high angle incident light.

4. The sensor of claim 1 , wherein the optical filter is less sensitive to the angle incidence of light than a micro-structured metal-dielectric filter.

5. The sensor of claim 1 , wherein the optical filter is a nanostructured filter.

6. The sensor of claim 1 , wherein the optical filter comprises layers of metal and oxides.

7. The sensor of claim 6 , wherein the layers of metal and oxides have a thickness configured to pass light within the bandpass region.

8. The sensor of claim 6 , wherein the layers of metal and oxides are deposited on the photodetector.

9. The sensor of claim 8 , wherein the layers of metal and oxides are deposited on the photodetector by magnetron sputter coating.

10. The sensor of claim 6 ,

wherein the photodetector includes an exit side opposite a receiving side, and

wherein the layers of metal and oxides are deposited on the exit side of the photodetector.

11. The sensor of claim 1 , wherein the bandpass region shifts by 20 nm or less as the angle of incidence of light received by the optical filter increases from 0 degrees to 89 degrees.

12. The sensor of claim 1 , further comprising:

an element configured to emit emission light toward the optical filter; and

a light source configured to irradiate excitation light to the element.

13. The sensor of claim 12 , wherein the element is positioned relative to a receiving surface of the optical filter such that at least a portion of the emission light reaches the optical filter as low angle of incidence light.

14. The sensor of claim 13 , wherein the low angle of incidence light has an angle of incidence less than or equal to 25 degrees.

15. The sensor of claim 13 , wherein the low angle of incidence light has an angle of incidence less than or equal to 20 degrees.

16. The sensor of claim 13 , wherein the low angle of incidence light has an angle of incidence less than or equal to 15 degrees.

17. The sensor of claim 13 , wherein the low angle of incidence light has an angle of incidence less than or equal to 10 degrees.

18. The sensor of claim 13 , wherein the low angle of incidence light has an angle of incidence less than or equal to 5 degrees.

19. The sensor of claim 1 , wherein the optical filter utilizes dichroic and absorptive filtering.

20. The sensor of claim 1 ,

wherein the photodetector is a first photodetector,

wherein the optical filter is a first optical filter,

wherein the bandpass region is a first bandpass region, and

wherein the sensor further comprises:

a second photodetector configured to:

convert different received light into a different current indicative of a different intensity of the different received light received by the second photodetector; and

a second optical filter configured to:

prevent different light having a wavelength outside a second bandpass region from reaching the second photodetector, and

pass different light having a wavelength within the second bandpass region to the second photodetector.

21. A method of detecting an analyte using a sensor, the method comprising:

irradiating, by a light source of the sensor, excitation light to an analyte indicator of the sensor;

emitting, by the analyte indicator, emission light to an optical filter of the sensor;

receiving, by the optical filter, light that includes the emission light emitted by the analyte indicator;

preventing, by the optical filter, first light, of the received light, having one or more of a wavelength outside a bandpass region or a high angle of incidence from reaching a photodetector of the sensor;

passing, by the optical filter, second light, of the received light, having a wavelength within the bandpass region to the photodetector,

wherein a percentage of light passed by the optical filter decreases as an angle of incidence of light increases from 0 degrees to 89 degrees, and

wherein an amplitude of transmission decreases as the angle of incidence of light increases; and

receiving, by the photodetector, the passed light.

22. A method of manufacturing an analyte sensor, the method comprising:

fabricating or mounting a photodetector in or on a substrate; and

forming an optical filter by depositing layers of metal and oxides on the photodetector,

wherein the optical filter is configured to prevent light having a wavelength outside a bandpass region from reaching the photodetector and to pass light having a wavelength within the bandpass region to the photodetector,

wherein a percentage of light passed through the optical filter decreases as an angle of incidence of light increases from 0 degrees to 89 degrees, and

wherein an amplitude of transmission decreases as the angle of incidence of light increases.